As illustrated in FIG. 1, for a variety of reasons an aircraft 1300 may be forced to make an emergency landing. During the emergency landing, the aircraft 1300 typically approaches a landing surface 1000 at an angle of attack AA of between approximately 10-degrees and approximately 12-degrees.
When the aircraft 1300 makes contact (e.g., impacts) the landing surface 1000 (e.g., at the angle of attack AA), the area (e.g., a contact surface) of the aircraft 1300 that makes initial contact with the landing surface 1000 (e.g., an initial contact surface 1302) is typically a distance D1 aft (rearward) of a center of gravity CG of the aircraft 1300. Shortly after impact (e.g., as the aircraft 1300 begins to slow), the surface of the aircraft 1300 in primary contact with the landing surface 1000 may move forward, but still remains aft of the center of gravity CG. For example, the contact surface that makes secondary contact with the landing surface 1000 (e.g., a secondary contact surface 1304) is typically located a distance D2 aft of a center of gravity CG of the aircraft 1300.
Upon contact with the landing surface 1000 (e.g., by the initial contact surface 1302 and then by the secondary contact surface 1304), a reaction force FR (having horizontal and vertical components) results from contact with the landing surface 1000 acting through the contact surface of the aircraft 1300 and an inertial force FI (having opposite horizontal and vertical components) results from the inertia of the aircraft 1300 acting through the center of gravity CG. At impact, the distance D1 between the inertial force FI and the reaction force FR tends to create a nose-down pitching moment M1. As the emergency landing continues, the distance D2 between the inertial force FI and the reaction force FR tends to continue this nose-down pitching moment M1. This nose-down pitching moment M1 may cause the aircraft 1300 rotate in a forward direction and drive a nose of the aircraft 1300 into the landing surface 1000.
During a ground forced landing (a gear-up or belly landing on the ground), the nose-down rotation of the aircraft 1300 may damage the aircraft 1300 and/or injure the pilot and flight crew, as the nose crashes into the ground. During a water ditching landing (a forced landing on water), this nose-down rotation may cause the aircraft 1300 to completely flip over, as the nose plows into the water, and bring the aircraft 1300 to rest in an inverted (upside down) position in the water. In this scenario, in addition to damaging the aircraft 1300, the pilot and flight crew may become trapped within the inverted, and submerged, aircraft 1300.
Accordingly, those skilled in the art continue with research and development efforts in the field of aircraft emergency landings.